Casio CZ/ VZ/ FZ - Pro Series

Hi all,

I own a CZ1 with an almost dead EL backlight. 

What I would like to know is:

1) is there any chance to hack the inverter circuit/transformer so that it could feed a couple LEDs which I plan to place besides the LCD? (more details on that below). AFAIK the input to the inverter is VDC, so maybe disabling the transformer and doing some extra stuff would get the point.

2) if 1 above is a no-no, where can I get appropriate current from for driving a couple bright LEDs? I've seen some posts where a brand new display with built-in LED backlight was retrofitted into non-backlit models like CZ1000. The on switch was mentioned, but I also saw that also pins 1 and 2 of the LCD can be used for that. Also, could I disable the inverter circuit so as to save some power?

My idea is to keep the existing LCD and fit it with a custom backlight. I've been doing some tests with a tiny rectangular piece of acrylic sanded on one side so as to diffuse light. I placed it where the EL foil used to be and lit it with a small LED lantern. Light gets effectively across it and the LCD gets softly lit so I think if I placed two strong-enough LEDs at both sides of the acrylic I would get a nice backlight.

I have only very basic electronics knowledge but am not afraid of soldering stuff. :)

Thanks very much in advance for any help.

Dave

On Wed, 2010-12-08 at 03:17 +0000, davidmochen wrote:
> Hi all,
> 
> I own a CZ1 with an almost dead EL backlight. 
> 
> What I would like to know is:
> 
> 1) is there any chance to hack the inverter circuit/transformer so
> that it could feed a couple LEDs which I plan to place besides the
> LCD? (more details on that below). AFAIK the input to the inverter is
> VDC, so maybe disabling the transformer and doing some extra stuff
> would get the point.

No, because the inverter takes a low voltage and steps it up to a couple
of hundred volts to drive the EL backlight and LEDs need about two
volts ;-)

Not only is it a bad idea to modify the inverter, it's not even
particularly necessary.

> 2) if 1 above is a no-no, where can I get appropriate current from for
> driving a couple bright LEDs? I've seen some posts where a brand new
> display with built-in LED backlight was retrofitted into non-backlit
> models like CZ1000. The on switch was mentioned, but I also saw that
> also pins 1 and 2 of the LCD can be used for that. Also, could I
> disable the inverter circuit so as to save some power?

Pick up a DC supply from just about anywhere, including as you say the
power leads to the LCD.  Wire the LEDs up with a suitable
current-limiting resistor which you can work out from the forward
voltage and current of the LED and the supply voltage.  Or, just run it
off the 5V rail with a 220 ohm resistor for each LED, that'll get you
about right.  Don't go much below about 100 ohms unless you're using a
very high-power LED, or you'll cook it.  Above about 680 ohms chances
are it'll be a bit too dim.

> My idea is to keep the existing LCD and fit it with a custom
> backlight. I've been doing some tests with a tiny rectangular piece of
> acrylic sanded on one side so as to diffuse light. I placed it where
> the EL foil used to be and lit it with a small LED lantern. Light gets
> effectively across it and the LCD gets softly lit so I think if I
> placed two strong-enough LEDs at both sides of the acrylic I would get
> a nice backlight.

You can get EL films for other gear like the Akai samplers.  I bet if
you send the old film to one of these guys on eBay they'd cut you a bit,
or just sell you an Akai backlight to cut up yourself.

> I have only very basic electronics knowledge but am not afraid of
> soldering stuff. :)
> 
> Thanks very much in advance for any help.

Well, you like old synthesizers so you're going to need to learn to
repair them some day ;-)

Gordon MM0YEQ

Hi Dave,

My microKORG XL uses little tiny yellow LED's and acrylic so this should work. Go here to this site for all the details for driving bright LED's from a power supply voltage ->

http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fled_info.htm

Don't forget to disconnect the inverter so nothing gets zapped. Some of them have 400 vac outputs. Let us know how it goes....

Good luck, Fran
--- In CZsynth@yahoogroups.com, "davidmochen" <davidmochen@...> wrote:

>
> Hi all,
> 
> I own a CZ1 with an almost dead EL backlight. 
> 
> What I would like to know is:
> 
> 1) is there any chance to hack the inverter circuit/transformer so that it could feed a couple LEDs which I plan to place besides the LCD? (more details on that below). AFAIK the input to the inverter is VDC, so maybe disabling the transformer and doing some extra stuff would get the point.
> 
> 2) if 1 above is a no-no, where can I get appropriate current from for driving a couple bright LEDs? I've seen some posts where a brand new display with built-in LED backlight was retrofitted into non-backlit models like CZ1000. The on switch was mentioned, but I also saw that also pins 1 and 2 of the LCD can be used for that. Also, could I disable the inverter circuit so as to save some power?
> 
> My idea is to keep the existing LCD and fit it with a custom backlight. I've been doing some tests with a tiny rectangular piece of acrylic sanded on one side so as to diffuse light. I placed it where the EL foil used to be and lit it with a small LED lantern. Light gets effectively across it and the LCD gets softly lit so I think if I placed two strong-enough LEDs at both sides of the acrylic I would get a nice backlight.
> 
> I have only very basic electronics knowledge but am not afraid of soldering stuff. :)
> 
> Thanks very much in advance for any help.
> 
> Dave
>

Hi Fran, Gordon,

Glad to see you are old-timers form the KorgPolyEx as well just like me! 
:) (waiting for my atomahawk kit to arrive...)

Thanks very much for your suggestions. I found the LED calculator pages 
very informative and useful. I would definitely like to know where the 
5V rail is, but if I can take voltage from then LCD power leads with no 
risk of the LCD getting less voltage than necessary that will be fine. I 
was thinking maybe I could draw current from the stage previous to the 
inverter-transformer (the low voltage) so I could even desolder the 
transformer. But then again, maybe I'm talking nonsense.

As I said, I have no formal knowledge of electronics but nevertheless 
managed to perform various repairs (including fixing pendrives or MP3 
players, almost doing microsurgery to them -- yes, in Argentina you do 
get to do that since electronics are a tad more expensive than in the 
USA). I've even did the MoogSlayer and FM-800 mods on my Poly 800 and 
they work perfectly.

Regarding EL foils, it's been only a couple days since I fitted my Korg 
01W with a new EL foil from Synthlights in Canada. Problem is, I live in 
Argentina and it took more than two months to receive the package (and 
it was in TERRIBLE conditions... luckily the foil works fine). So I want 
to try this alternative solution.

Thanks again for your time and help!

Dave



On 08/12/2010 06:28, Gordon JC Pearce wrote:
>
> On Wed, 2010-12-08 at 03:17 +0000, davidmochen wrote:
> > Hi all,
> >
> > I own a CZ1 with an almost dead EL backlight.
> >
> > What I would like to know is:
> >
> > 1) is there any chance to hack the inverter circuit/transformer so
> > that it could feed a couple LEDs which I plan to place besides the
> > LCD? (more details on that below). AFAIK the input to the inverter is
> > VDC, so maybe disabling the transformer and doing some extra stuff
> > would get the point.
>
> No, because the inverter takes a low voltage and steps it up to a couple
> of hundred volts to drive the EL backlight and LEDs need about two
> volts ;-)
>
> Not only is it a bad idea to modify the inverter, it's not even
> particularly necessary.
>
> > 2) if 1 above is a no-no, where can I get appropriate current from for
> > driving a couple bright LEDs? I've seen some posts where a brand new
> > display with built-in LED backlight was retrofitted into non-backlit
> > models like CZ1000. The on switch was mentioned, but I also saw that
> > also pins 1 and 2 of the LCD can be used for that. Also, could I
> > disable the inverter circuit so as to save some power?
>
> Pick up a DC supply from just about anywhere, including as you say the
> power leads to the LCD. Wire the LEDs up with a suitable
> current-limiting resistor which you can work out from the forward
> voltage and current of the LED and the supply voltage. Or, just run it
> off the 5V rail with a 220 ohm resistor for each LED, that'll get you
> about right. Don't go much below about 100 ohms unless you're using a
> very high-power LED, or you'll cook it. Above about 680 ohms chances
> are it'll be a bit too dim.
>
> > My idea is to keep the existing LCD and fit it with a custom
> > backlight. I've been doing some tests with a tiny rectangular piece of
> > acrylic sanded on one side so as to diffuse light. I placed it where
> > the EL foil used to be and lit it with a small LED lantern. Light gets
> > effectively across it and the LCD gets softly lit so I think if I
> > placed two strong-enough LEDs at both sides of the acrylic I would get
> > a nice backlight.
>
> You can get EL films for other gear like the Akai samplers. I bet if
> you send the old film to one of these guys on eBay they'd cut you a bit,
> or just sell you an Akai backlight to cut up yourself.
>
> > I have only very basic electronics knowledge but am not afraid of
> > soldering stuff. :)
> >
> > Thanks very much in advance for any help.
>
> Well, you like old synthesizers so you're going to need to learn to
> repair them some day ;-)
>
> Gordon MM0YEQ
>
> 


[Non-text portions of this message have been removed]

Hi group,

I've uploaded some pix showing my LCD mod for my CZ1. 
http://groups.yahoo.com/group/CZsynth/photos/album/1481989801/pic/list

Basically, I picked up 5v from pins 1 and 2 of the LCD. Got 4 5mm LEDs 
and a resistor (55 ohm; I figured the value using an online LED 
calculator [thanks, fran!]).

In order to have the light evenly spread below the LCD glass, I got a 
small piece of acrylic which I sanded with a fine grain sandpaper so as 
to be able to fit it under the LCD and also to refract the light. I 
wanted a colored acrylic, like yellow or green, but only found 
transparent. I placed a strip of white paper below the acrylic so that 
light would be reflected upwards. Smooth side of the acrylic went on the 
bottom side (in contact with the paper) while sanded side faced top 
(right below the LCD glass).

The LEDs are blue (yellow looked good but didn't seem to be strong, so...)

Display has a "violeter" hue than in the first pix. In total darkness, 
it is hard to read the characters if you look from above the keyboard. 
If you look from a normal playing angle, though, it is readable indeed. 
I set contrast to the max. If I get tired of blue I will try yellow next 
time :)

There is some light leakage from the LEDs that you can see in the pix. I 
fixed that later by sealing the space between LCD and plastic chassis in 
the top panel of the CZ1.

Thanks Gordon and Fran for your input and hope you guys like it!

Dave

On 08/12/2010 08:01, narfman96 wrote:
>
> Hi Dave,
>
> My microKORG XL uses little tiny yellow LED's and acrylic so this 
> should work. Go here to this site for all the details for driving 
> bright LED's from a power supply voltage ->
>
> http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fled_info.htm 
> <http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fled_info.htm>
>
> Don't forget to disconnect the inverter so nothing gets zapped. Some 
> of them have 400 vac outputs. Let us know how it goes....
>
> Good luck, Fran
> --- In CZsynth@yahoogroups.com <mailto:CZsynth%40yahoogroups.com>, 
> "davidmochen" <davidmochen@...> wrote:
> >
> > Hi all,
> >
> > I own a CZ1 with an almost dead EL backlight.
> >
> > What I would like to know is:
> >
> > 1) is there any chance to hack the inverter circuit/transformer so 
> that it could feed a couple LEDs which I plan to place besides the 
> LCD? (more details on that below). AFAIK the input to the inverter is 
> VDC, so maybe disabling the transformer and doing some extra stuff 
> would get the point.
> >
> > 2) if 1 above is a no-no, where can I get appropriate current from 
> for driving a couple bright LEDs? I've seen some posts where a brand 
> new display with built-in LED backlight was retrofitted into 
> non-backlit models like CZ1000. The on switch was mentioned, but I 
> also saw that also pins 1 and 2 of the LCD can be used for that. Also, 
> could I disable the inverter circuit so as to save some power?
> >
> > My idea is to keep the existing LCD and fit it with a custom 
> backlight. I've been doing some tests with a tiny rectangular piece of 
> acrylic sanded on one side so as to diffuse light. I placed it where 
> the EL foil used to be and lit it with a small LED lantern. Light gets 
> effectively across it and the LCD gets softly lit so I think if I 
> placed two strong-enough LEDs at both sides of the acrylic I would get 
> a nice backlight.
> >
> > I have only very basic electronics knowledge but am not afraid of 
> soldering stuff. :)
> >
> > Thanks very much in advance for any help.
> >
> > Dave
> >
>
> 


[Non-text portions of this message have been removed]

Dave,

This is awesome!!! I archived your pics so I can apply this to other el-foil displays. I looked real quick online and Radio Shack has rectangular super bright blue leds that would fit in most any display. I probably could bead blast the acrylic at work too.

Thanks so much for sharing this and taking these pics!  Fran 

--- In CZsynth@yahoogroups.com, David Mochen <davidmochen@...> wrote:

>
> Hi group,
> 
> I've uploaded some pix showing my LCD mod for my CZ1. 
> http://groups.yahoo.com/group/CZsynth/photos/album/1481989801/pic/list
> 
> Basically, I picked up 5v from pins 1 and 2 of the LCD. Got 4 5mm LEDs 
> and a resistor (55 ohm; I figured the value using an online LED 
> calculator [thanks, fran!]).
> 
> In order to have the light evenly spread below the LCD glass, I got a 
> small piece of acrylic which I sanded with a fine grain sandpaper so as 
> to be able to fit it under the LCD and also to refract the light. I 
> wanted a colored acrylic, like yellow or green, but only found 
> transparent. I placed a strip of white paper below the acrylic so that 
> light would be reflected upwards. Smooth side of the acrylic went on the 
> bottom side (in contact with the paper) while sanded side faced top 
> (right below the LCD glass).
> 
> The LEDs are blue (yellow looked good but didn't seem to be strong, so...)
> 
> Display has a "violeter" hue than in the first pix. In total darkness, 
> it is hard to read the characters if you look from above the keyboard. 
> If you look from a normal playing angle, though, it is readable indeed. 
> I set contrast to the max. If I get tired of blue I will try yellow next 
> time :)
> 
> There is some light leakage from the LEDs that you can see in the pix. I 
> fixed that later by sealing the space between LCD and plastic chassis in 
> the top panel of the CZ1.
> 
> Thanks Gordon and Fran for your input and hope you guys like it!
> 
> Dave
> 
> On 08/12/2010 08:01, narfman96 wrote:
> >
> > Hi Dave,
> >
> > My microKORG XL uses little tiny yellow LED's and acrylic so this 
> > should work. Go here to this site for all the details for driving 
> > bright LED's from a power supply voltage ->
> >
> > http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fled_info.htm 
> > <http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fled_info.htm>
> >
> > Don't forget to disconnect the inverter so nothing gets zapped. Some 
> > of them have 400 vac outputs. Let us know how it goes....
> >
> > Good luck, Fran
> > --- In CZsynth@yahoogroups.com <mailto:CZsynth%40yahoogroups.com>, 
> > "davidmochen" <davidmochen@> wrote:
> > >
> > > Hi all,
> > >
> > > I own a CZ1 with an almost dead EL backlight.
> > >
> > > What I would like to know is:
> > >
> > > 1) is there any chance to hack the inverter circuit/transformer so 
> > that it could feed a couple LEDs which I plan to place besides the 
> > LCD? (more details on that below). AFAIK the input to the inverter is 
> > VDC, so maybe disabling the transformer and doing some extra stuff 
> > would get the point.
> > >
> > > 2) if 1 above is a no-no, where can I get appropriate current from 
> > for driving a couple bright LEDs? I've seen some posts where a brand 
> > new display with built-in LED backlight was retrofitted into 
> > non-backlit models like CZ1000. The on switch was mentioned, but I 
> > also saw that also pins 1 and 2 of the LCD can be used for that. Also, 
> > could I disable the inverter circuit so as to save some power?
> > >
> > > My idea is to keep the existing LCD and fit it with a custom 
> > backlight. I've been doing some tests with a tiny rectangular piece of 
> > acrylic sanded on one side so as to diffuse light. I placed it where 
> > the EL foil used to be and lit it with a small LED lantern. Light gets 
> > effectively across it and the LCD gets softly lit so I think if I 
> > placed two strong-enough LEDs at both sides of the acrylic I would get 
> > a nice backlight.
> > >
> > > I have only very basic electronics knowledge but am not afraid of 
> > soldering stuff. :)
> > >
> > > Thanks very much in advance for any help.
> > >
> > > Dave
> > >
> >
> > 
> 
> 
> [Non-text portions of this message have been removed]
>

Hi Fran,

Glad you like it. As an advice, I would suggest using light-colored LEDs 
for better contrast with characters.

Best,

D

On 20/12/2010 11:05, narfman96 wrote:
>
> Dave,
>
> This is awesome!!! I archived your pics so I can apply this to other 
> el-foil displays. I looked real quick online and Radio Shack has 
> rectangular super bright blue leds that would fit in most any display. 
> I probably could bead blast the acrylic at work too.
>
> Thanks so much for sharing this and taking these pics! Fran
>
> --- In CZsynth@yahoogroups.com <mailto:CZsynth%40yahoogroups.com>, 
> David Mochen <davidmochen@...> wrote:
> >
> > Hi group,
> >
> > I've uploaded some pix showing my LCD mod for my CZ1.
> > http://groups.yahoo.com/group/CZsynth/photos/album/1481989801/pic/list
> >
> > Basically, I picked up 5v from pins 1 and 2 of the LCD. Got 4 5mm LEDs
> > and a resistor (55 ohm; I figured the value using an online LED
> > calculator [thanks, fran!]).
> >
> > In order to have the light evenly spread below the LCD glass, I got a
> > small piece of acrylic which I sanded with a fine grain sandpaper so as
> > to be able to fit it under the LCD and also to refract the light. I
> > wanted a colored acrylic, like yellow or green, but only found
> > transparent. I placed a strip of white paper below the acrylic so that
> > light would be reflected upwards. Smooth side of the acrylic went on 
> the
> > bottom side (in contact with the paper) while sanded side faced top
> > (right below the LCD glass).
> >
> > The LEDs are blue (yellow looked good but didn't seem to be strong, 
> so...)
> >
> > Display has a "violeter" hue than in the first pix. In total darkness,
> > it is hard to read the characters if you look from above the keyboard.
> > If you look from a normal playing angle, though, it is readable indeed.
> > I set contrast to the max. If I get tired of blue I will try yellow 
> next
> > time :)
> >
> > There is some light leakage from the LEDs that you can see in the 
> pix. I
> > fixed that later by sealing the space between LCD and plastic 
> chassis in
> > the top panel of the CZ1.
> >
> > Thanks Gordon and Fran for your input and hope you guys like it!
> >
> > Dave
> >
> > On 08/12/2010 08:01, narfman96 wrote:
> > >
> > > Hi Dave,
> > >
> > > My microKORG XL uses little tiny yellow LED's and acrylic so this
> > > should work. Go here to this site for all the details for driving
> > > bright LED's from a power supply voltage ->
> > >
> > > 
> http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fled_info.htm 
> <http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fled_info.htm> 
>
> > > 
> <http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fled_info.htm 
> <http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fled_info.htm>>
> > >
> > > Don't forget to disconnect the inverter so nothing gets zapped. Some
> > > of them have 400 vac outputs. Let us know how it goes....
> > >
> > > Good luck, Fran
> > > --- In CZsynth@yahoogroups.com <mailto:CZsynth%40yahoogroups.com> 
> <mailto:CZsynth%40yahoogroups.com>,
> > > "davidmochen" <davidmochen@> wrote:
> > > >
> > > > Hi all,
> > > >
> > > > I own a CZ1 with an almost dead EL backlight.
> > > >
> > > > What I would like to know is:
> > > >
> > > > 1) is there any chance to hack the inverter circuit/transformer so
> > > that it could feed a couple LEDs which I plan to place besides the
> > > LCD? (more details on that below). AFAIK the input to the inverter is
> > > VDC, so maybe disabling the transformer and doing some extra stuff
> > > would get the point.
> > > >
> > > > 2) if 1 above is a no-no, where can I get appropriate current from
> > > for driving a couple bright LEDs? I've seen some posts where a brand
> > > new display with built-in LED backlight was retrofitted into
> > > non-backlit models like CZ1000. The on switch was mentioned, but I
> > > also saw that also pins 1 and 2 of the LCD can be used for that. 
> Also,
> > > could I disable the inverter circuit so as to save some power?
> > > >
> > > > My idea is to keep the existing LCD and fit it with a custom
> > > backlight. I've been doing some tests with a tiny rectangular 
> piece of
> > > acrylic sanded on one side so as to diffuse light. I placed it where
> > > the EL foil used to be and lit it with a small LED lantern. Light 
> gets
> > > effectively across it and the LCD gets softly lit so I think if I
> > > placed two strong-enough LEDs at both sides of the acrylic I would 
> get
> > > a nice backlight.
> > > >
> > > > I have only very basic electronics knowledge but am not afraid of
> > > soldering stuff. :)
> > > >
> > > > Thanks very much in advance for any help.
> > > >
> > > > Dave
> > > >
> > >
> > >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
> 


[Non-text portions of this message have been removed]